Comment 10 for bug 1956885

Hi,

Thanks for inputs regarding change in behavior of 20.04 vs 22.04, I will
look at the verify function implementation.

Thanks,
Prafulla

On Tue, Aug 16, 2022 at 1:11 PM Loic Yhuel <email address hidden>
wrote:

> Everything is in the description : the "verify" method isn't correct in
> the Broadcom library (it is synchronous, it must be asynchronous).
> On 20.04, the login would always use "identify", so the problem was hidden.
> But due to the libprintfd change, on 22.04 the login uses "verify" when
> only one finger has been enrolled (and still "identify" if two or more
> fingers have been enrolled).
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1956885
>
> Title:
> Incorrect verify implementation, unable to verify on one finger
>
> Status in libfprint-2-tod1-broadcom:
> Confirmed
> Status in OEM Priority Project:
> Confirmed
> Status in libfprint package in Ubuntu:
> Confirmed
>
> Bug description:
> The closed-source library blocks on synchronous USB transfers in its
> "verify" method (at least, there might be others with the same issue).
> The "identify" one is correct (asynchronous).
>
> As a result :
> $ fprintd-verify
> Using device /net/reactivated/Fprint/Device/0
> Listing enrolled fingers:
> - #0: right-index-finger
> (finger pressed)
> Verify started!
> Verifying: right-index-finger
> (blocked)
>
> "Verify started!" should happen immediately, but the code libfprint code
> waits for fp_device_verify to return, which only happens when the finger is
> pressed with this driver.
> The verify success message is sent during the call, so it is ignored.
>
> "fprintd-verify -f any" and pam-fprintd use fp_device_identify, so they
> work correctly.
> But with
> https://gitlab.freedesktop.org/libfprint/fprintd/-/commit/fc65055279 (so
> I suppose on jammy), the "verify" method will be used instead if only one
> finger is enrolled.
>
> TL,DR: the fingerprint reader appears to mostly work on focal, but
> starting with jammy it won't unless at least two fingers are enrolled.
>
> Note that this is tested on a Dell Latitude 5521, but the issue should
> be the same with all Broadcom fingerprint readers using this library.
>
> Duplicate bug #1981974
>
> To manage notifications about this bug go to:
>
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>
>

--
Thanks,
Prafulla Kota
9866544810